Stackable integrated circuit package system

ABSTRACT

A stackable integrated circuit package system includes: a substrate having a first side and a second side opposite the first side, the substrate having a cavity provided therein; a first integrated circuit die in the cavity with a first interconnect extending out from the cavity without connection and a second interconnect connected to the first side; a first mold compound to cover the first integrated circuit die, the second interconnect, and a portion of the first interconnect; a second integrated circuit die mounted to the first integrated circuit die with a third interconnect connected to the second side; a second mold compound to cover the second integrated circuit die and the third interconnect; and external interconnects, not encapsulated by the second encapsulant, mounted on the second side.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This is a divisional of co-pending U.S. patent application Ser. No.11/307,906 filed Feb. 27, 2006.

TECHNICAL FIELD

The present invention relates generally to integrated circuit packagesand more particularly to a stackable integrated circuit package system.

BACKGROUND ART

Modern consumer electronics, such as smart phones, personal digitalassistants, and location based services devices, as well as enterpriseelectronics, such as servers and storage arrays, are packing moreintegrated circuits into an ever shrinking physical space withexpectations for decreasing cost. Numerous technologies have beendeveloped to meet these requirements. Some of the research anddevelopment strategies focus on new package technologies while othersfocus on improving the existing and mature package technologies.Research and development in the existing package technologies may take amyriad of different directions.

One proven way to reduce cost is to use package technologies withexisting manufacturing methods and equipments. Paradoxically, the reuseof existing manufacturing processes does not typically result in thereduction of package dimensions. Existing packaging technologiesstruggle to cost effectively meet the ever demanding integration oftoday's integrated circuits and packages.

In response to the demands for improved packaging, many innovativepackage designs have been conceived and brought to market. Themulti-chip module has achieved a prominent role in reducing the boardspace used by modern electronics. However, multi-chip modules, whethervertically or horizontally arranged, can also present problems becausethey usually must be assembled before the component chips and chipconnections can be tested. That is, because the electrical bond pads ona die are so small, it is difficult to test die before assembly onto asubstrate. Thus, when die are mounted and connected individually, thedie and connections can be tested individually, and only known-good-die(“KGD”) that is free of defects is then assembled into larger circuits.A fabrication process that uses KGD is therefore more reliable and lessprone to assembly defects introduced due to bad die. With conventionalmulti-chip modules, however, the die cannot be individually identifiedas KGD before final assembly, leading to KGD inefficiencies and assemblyprocess yield problems.

Numerous package approaches stack multiple integrated circuits, packagelevel stacking, or package on package (POP). KGD and assembly processyields are not an issue since each package can be tested prior toassembly, allowing KGD to be used in assembling the stack. But stackingintegrated devices, package-on-package, or a combination thereof hasassembly process difficulties caused by these packages having limitedinput and output (I/O). Current packages also do not provide theflexibility to support the various integration and stacking optionsdescribed earlier with the higher I/O count support.

Thus, a need still remains for a stackable integrated circuit packagesystem providing low cost manufacturing, improved yields, reduce theintegrated circuit package dimensions and flexible stacking andintegration configurations. In view of the ever-increasing need to savecosts and improve efficiencies, it is more and more critical thatanswers be found to these problems.

Solutions to these problems have been long sought but prior developmentshave not taught or suggested any solutions and, thus, solutions to theseproblems have long eluded those skilled in the art.

DISCLOSURE OF THE INVENTION

The present invention provides a stackable integrated circuit packagesystem including: a substrate having a first side and a second sideopposite the first side, the substrate having a cavity provided therein;a first integrated circuit die in the cavity with a first interconnectextending out from the cavity without connection and a secondinterconnect connected to the first side; a first mold compound to coverthe first integrated circuit die, the second interconnect, and a portionof the first interconnect; a second integrated circuit die mounted tothe first integrated circuit die with a third interconnect connected tothe second side; a second mold compound to cover the second integratedcircuit die and the third interconnect; and external interconnects, notencapsulated by the second encapsulant, mounted on the second side.

Certain embodiments of the invention have other aspects in addition toor in place of those mentioned or obvious from the above. The aspectswill become apparent to those skilled in the art from a reading of thefollowing detailed description when taken with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a first stackable integrated circuitpackage system in an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a second stackable integratedcircuit package system in an alternative embodiment of the presentinvention;

FIG. 3 is a cross-sectional view of a third stackable integrated circuitpackage system in another alternative embodiment of the presentinvention;

FIG. 4 is a cross-sectional view of a fourth stackable integratedcircuit package system in yet another alternative embodiment of thepresent invention;

FIG. 5 is a cross-sectional view of a first integrated circuitpackage-on-package system having the first stackable integrated circuitpackage system;

FIG. 6 is a cross-sectional view of a second integrated circuitpackage-on-package system having the second stackable integrated circuitpackage system;

FIG. 7 is a cross-sectional view of the substrate in a pre-die-attachphase;

FIG. 8 is the structure of FIG. 7 in a first die-attach phase;

FIG. 9 is the structure of FIG. 8 in a first encapsulation phase;

FIG. 10 is the structure of FIG. 9 in a tape removal phase;

FIG. 11 is the structure of FIG. 10 a second die-attach phase;

FIG. 12 is the structure of FIG. 11 in a second encapsulation phase;

FIG. 13 is the structure of FIG. 12 in an external connectivity attachphase;

FIG. 14 is the structure of FIG. 13 in a package mounting phase; and

FIG. 15 is a flow chart of a stackable integrated circuit package systemfor manufacture of the stackable integrated circuit package system in anembodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

In the following description, numerous specific details are given toprovide a thorough understanding of the invention. However, it will beapparent that the invention may be practiced without these specificdetails. In order to avoid obscuring the present invention, somewell-known system configurations, and process steps are not disclosed indetail. Likewise, the drawings showing embodiments of the apparatus aresemi-diagrammatic and not to scale and, particularly, some of thedimensions are for the clarity of presentation and are shown greatlyexaggerated in the figures. The same numbers are used in all the figuresto relate to the same elements.

The term “horizontal” as used herein is defined as a plane parallel tothe conventional integrated circuit surface, regardless of itsorientation. The term “vertical” refers to a direction perpendicular tothe horizontal as just defined. Terms, such as “above”, “below”,“bottom”, “top”, “side” (as in “sidewall”), “higher”, “lower”, “upper”,“over”, and “under”, are defined with respect to the horizontal plane.The term “on” means there is direct contact among elements.

The term “processing” as used herein includes deposition of material,patterning, exposure, development, etching, cleaning, molding, and/orremoval of the material or as required in forming a described structure.

Referring now to FIG. 1, therein is shown a cross-sectional view of afirst stackable integrated circuit package system 100 in an embodimentof the present invention. A first integrated circuit die 102, such as aflip chip or a bumped chip, has first interconnects 104, such as solderbumps, on a first active side 106. The first integrated circuit die 102is located in a cavity 108 of a substrate 110, such as an organic orinorganic substrate, with the first interconnects 104 extending out fromthe cavity 108 without connection. Second interconnects 112, such asbond wires, are electrically connected between the first integratedcircuit die 102 and a first side 114 of the substrate 110. A secondintegrated circuit die 116 is attached to a first non-active side 118 ofthe first integrated circuit die 102. Third interconnects 120, such asbond wires, are electrically connected between the second integratedcircuit die 116 and a second side 122 of the substrate 110.

A first mold compound 124, such as an epoxy mold compound (EMC),encapsulates the first integrated circuit die 102 and the secondinterconnects 112 and fills the cavity 108. The first mold compound 124also surrounds and exposes the first interconnects 104 for furtherconnections. The first side 114 is substantially covered by the firstmold compound 124.

A second mold compound 126, such as an epoxy mold compound (EMC),encapsulates the second integrated circuit die 116 and the thirdinterconnects 120. The second mold compound 126 forms a hermetic sealwith the first mold compound 124 for the first integrated circuit die102 and the second integrated circuit die 116. The second mold compound126 covers the second side 122 near the cavity 108. Externalinterconnects 128, such as solder balls, are attached to the second side122 and not encapsulated by the second mold compound 126. The first moldcompound 124 and the second mold compound 126 may be the same materialor may be different.

The substrate 110 has bond sites (not shown) in the first side 114 andthe second side 122 for connections with the second interconnects 112and the third interconnects 120, respectively. The bond sites in thefirst side 114 are part of a conductive layer (not shown) of the firstside 114. Similarly, the bond sites in the second side 122 are part ofanother conductive layer (not shown) of the second side 122. Electricalvias 130 connect the conductive layers at predetermined locations. Aninsulator layer 132, such as a dielectric layer, surrounds theelectrical vias 130 and separates the conductive layers.

Referring now to FIG. 2, therein is shown a cross-sectional view of asecond stackable integrated circuit package system 200 in an alternativeembodiment of the present invention. A first integrated circuit die 202,such as a flip chip or a bumped chip, has first interconnects 204, suchas solder bumps, on a first active side 206. The first integratedcircuit die 202 is located in a cavity 208 of a substrate 210, such asan organic or inorganic substrate. Second interconnects 212, such asbond wires, is attached between the first integrated circuit die 202 anda first side 214 of the substrate 210. A second integrated circuit die216 is attached to a first non-active side 218 of the first integratedcircuit die 202. Third interconnects 220, such as bond wires, areattached between the second integrated circuit die 216 and a second side222 of the substrate 210.

A first mold compound 224, such as an epoxy mold compound (EMC),encapsulates the first integrated circuit die 202 and the secondinterconnects 212 and fills the cavity 208. The first mold compound 224also surrounds and exposes the first interconnects 204 for furtherconnections. The first mold compound 224 covers the first side 214proximate the cavity 208.

A second mold compound 226, such as an epoxy mold compound (EMC),encapsulates the second integrated circuit die 216 and the thirdinterconnects 220. The second mold compound 226 forms a hermetic sealwith the first mold compound 224 for the first integrated circuit die202 and the second integrated circuit die 216. The second mold compound226 covers the second side 222 near the proximity of the cavity 208 anddoes not obstruct external interconnects 228, such as solder balls,attached to the second side 222. The first mold compound 224 and thesecond mold compound 226 may be the same material or may be different.

The substrate 210 has bond sites (not shown) in the first side 214 andthe second side 222 for connections with the second interconnects 212and the third interconnects 220, respectively. The bond sites in thefirst side 214 are part of a conductive layer (not shown) of the firstside 214. Similarly, the bond sites in the second side 222 are part ofanother conductive layer (not shown) of the second side 222. Electricalvias 230 connect the conductive layers at predetermined locations. Aninsulator layer 232, such as a dielectric layer, surrounds theelectrical vias 230 and separates the conductive layers.

Referring now to FIG. 3, therein is shown a cross-sectional view of athird stackable integrated circuit package system 300 in anotheralternative embodiment of the present invention. A first integratedcircuit die 302, such as a flip chip or a bumped chip, has firstinterconnects 304, such as solder bumps, on a first active side 306. Thefirst integrated circuit die 302 is located in a cavity 308 of asubstrate 310, such as an organic or inorganic substrate. Secondinterconnects 312, such as bond wires, is attached between the firstintegrated circuit die 302 and a first side 314 of the substrate 310. Asecond integrated circuit die 316 is attached to a first non-active side318 of the first integrated circuit die 302. Third interconnects 320,such as bond wires, are attached between the second integrated circuitdie 316 and a second side 322 of the substrate 310.

An encapsulant 324, such as a glob top, covers the first integratedcircuit die 302 and the second interconnects 312 and fills the cavity308. The encapsulant 324 also surrounds and exposes the firstinterconnects 304 for further connections. The first side 314 issubstantially covered by the encapsulant 324. The encapsulant 324 coversthe first side 314 proximate the cavity 308. The encapsulant 324provides stress relief.

A first mold compound 326, such as an epoxy mold compound (EMC),surrounds and exposes the encapsulant 324 while leaving the firstinterconnects 304 exposed for further connections. The first side 314 issubstantially covered by the first mold compound 326.

A second mold compound 328, such as an epoxy mold compound (EMC),encapsulates the second integrated circuit die 316 and the thirdinterconnects 320. The second mold compound 328 forms a hermetic sealwith the first mold compound 326 for the first integrated circuit die302 and the second integrated circuit die 316. The second mold compound328 covers the second side 322 near the proximity of the cavity 308 anddoes not obstruct external interconnects 330, such as solder balls,attached to the second side 322. The first mold compound 326 and thesecond mold compound 328 may be the same material or may be different.

The substrate 310 has bond sites (not shown) in the first side 314 andthe second side 322 for connections with the second interconnects 312and the third interconnects 320, respectively. The bond sites in thefirst side 314 are part of a conductive layer (not shown) of the firstside 314. Similarly, the bond sites in the second side 322 are part ofanother conductive layer (not shown) of the second side 322. Electricalvias 332 connect the conductive layers at predetermined locations. Aninsulator layer 334, such as a dielectric layer, surrounds theelectrical vias 332 and separates the conductive layers.

Referring now to FIG. 4, therein is shown a cross-sectional view of afourth stackable integrated circuit package system 400 in yet anotheralternative embodiment of the present invention. A first integratedcircuit die 402, such as a flip chip or a bumped chip, has firstinterconnects 404, such as solder bumps, on a first active side 406. Thefirst integrated circuit die 402 is located in a cavity 408 of asubstrate 410, such as an organic or inorganic substrate. Secondinterconnects 412, such as bond wires, is attached between the firstintegrated circuit die 402 and a first side 414 of the substrate 410.

A second integrated circuit die 416, such as a flip chip or a bumpedchip, has the first interconnects 404, such as solder bumps, on a secondactive side 418. The second integrated circuit die 416 is attached to afirst non-active side 420 of the first integrated circuit die 402. Thirdinterconnects 422, such as bond wires, is attached between the secondintegrated circuit die 416 and a second side 424 of the substrate 410.

A first mold compound 426, such as an epoxy mold compound (EMC),encapsulates the first integrated circuit die 402 and the secondinterconnects 412 and fills the cavity 408. The first mold compound 426also surrounds and exposes the first interconnects 404 for furtherconnections. The first side 414 is substantially covered by the firstmold compound 426.

A second mold compound 428, such as an epoxy mold compound (EMC),encapsulates the second integrated circuit die 416 and the thirdinterconnects 422. The second mold compound 428 also surrounds andexposes the first interconnects 404 of the second integrated circuit die416 for further connections. The second mold compound 428 forms ahermetic seal with the first mold compound 426 for the first integratedcircuit die 402 and the second integrated circuit die 416. The secondmold compound 428 covers the second side 424 near the proximity of thecavity 408 and does not obstruct external interconnects 430, such assolder balls, attached to the second side 424. The first mold compound426 and the second mold compound 428 may be the same material or may bedifferent.

The substrate 410 has bond sites (not shown) in the first side 414 andthe second side 424 for connections with the second interconnects 412and the third interconnects 422, respectively. The bond sites in thefirst side 414 are part of a conductive layer (not shown) of the firstside 414. Similarly, the bond sites in the second side 424 are part ofanother conductive layer (not shown) of the second side 424. Electricalvias 432 connect the conductive layers at predetermined locations. Aninsulator layer 434, such as a dielectric layer, surrounds theelectrical vias 432 and separates the conductive layers.

Referring now to FIG. 5, therein is shown a cross-sectional view of afirst integrated circuit package-on-package system 500 having the firststackable integrated circuit package system 100. A top package 502, suchas a leaded, arrayed, system in package (SIP), leadless, or stackedintegrated circuit package, is mounted on the first stackable integratedcircuit package system 100.

The top package 502 has a top integrated circuit die 504 mounted on atop substrate 506. Top internal interconnects 508, such as bond wires,is attached between the top integrated circuit die 504 and a top side510 of the top substrate 506. A top mold compound 512 encapsulates thetop integrated circuit die 504 and the top internal interconnects 508 tothe top side 510.

The top substrate 506 has bond sites (not shown) in the top side 510 anda bottom side 514 of the top substrate 506 for connections with the topinternal interconnects 508 and top external interconnects 516,respectively. The top external interconnects 516 is attached to thefirst interconnects 104. The bond sites in the top side 510 are part ofa conductive layer (not shown) of the top side 510. Similarly, the bondsites in the bottom side 514 are part of another conductive layer (notshown) of the bottom side 514. Electrical vias 520 connect theconductive layers at predetermined locations. An insulator layer 522,such as a dielectric layer, surrounds the electrical vias 520 andseparates the conductive layers.

The first integrated circuit die 102 may direct signals from the toppackage 502 to circuitry (not shown) of the first integrated circuit die102 and subsequently to the next system level (not shown), such as aprinted circuit board, using flex-on-chip (FOC) technology. The firstintegrated circuit die 102 may provide signal routing from the toppackage 502 on the first stackable integrated circuit package system 100to the next system level in a daisy chain transmission usingredistribution layer (RDL) technology serving as a dummysubstrate/interposer. The first integrated circuit die 102 furtherprovides signal routing from the top package 502 on the first stackableintegrated circuit package system 100, via circuitry of the firstintegrated circuit die 102, to the next system level using RDLtechnology.

Referring now to FIG. 6, therein is shown a cross-sectional view of asecond integrated circuit package-on-package system 600 having thesecond stackable integrated circuit package system 200. A top package602, such as a leaded, arrayed, system in package (SIP), leadless, orstacked integrated circuit package, is mounted on the second stackableintegrated circuit package system 200.

The top package 602 has a top integrated circuit die 604 mounted on atop substrate 606. Top internal interconnects 608, such as bond wires,is attached between the top integrated circuit die 604 and a top side610 of the top substrate 606. A top mold compound 612 encapsulates thetop integrated circuit die 604 and the top internal interconnects 608 tothe top side 610.

The top substrate 606 has bond sites (not shown), in the top side 610 ofthe top substrate 606, for connections with the top internalinterconnects 608. The top substrate 606 has bond sites (not shown) in abottom side 614 of the top substrate 606 for connections with first topexternal interconnects 616 and second top external interconnects 618.The first top external interconnects 616 is attached to the firstinterconnects 204. The second top external interconnects 618 is attachedto the substrate 210 of the second stackable integrated circuit packagesystem 200.

The bond sites in the top side 610 are part of a conductive layer (notshown) of the top side 610. Similarly, the bond sites in the bottom side614 are part of another conductive layer (not shown) of the bottom side614. Electrical vias 622 connect the conductive layers at predeterminedlocations. An insulator layer 624 such as a dielectric layer, surroundsthe electrical vias 622 and separates the conductive layers.

The first integrated circuit die 202 may direct signals from the toppackage 602 to circuitry (not shown) of the first integrated circuit die202 and subsequently to the next system level (not shown), such as aprinted circuit board, using flex-on-chip (FOC) technology. The firstintegrated circuit die 202 may provide signal routing from the toppackage 602 on the second stackable integrated circuit package system200 to the next system level in a daisy chain transmission usingredistribution layer (RDL) technology serving as a dummysubstrate/interposer. The first integrated circuit die 202 furtherprovides signal routing from the top package 602 on the second stackableintegrated circuit package system 200, via circuitry of the firstintegrated circuit die 202, to the next system level using RDLtechnology.

Referring now to FIG. 7, therein is shown a cross-sectional view of asubstrate structure 700 in an embodiment of the present invention. Thecross-sectional view depicts an instance of the substrate 110 of thesubstrate structure 700. A protective tape 702 is attached to the secondside 122 of the substrate 110. The protective tape 702 has sufficientstructural rigidity to remain planar under the cavity 108.

Referring now to FIG. 8, therein is shown the structure of FIG. 7 in afirst die-attach phase. The first integrated circuit die 102 having thefirst interconnects 104 thereon is placed in the cavity 108 and attachedto the protective tape 702. The second interconnects 112 are attachedbetween the first side 114 of the substrate 110 and the first activeside 106 of the first integrated circuit die 102.

Referring now to FIG. 9, therein is shown the structure of FIG. 8 in afirst encapsulation phase. The first mold compound 124 encapsulates thefirst integrated circuit die 102, the first interconnects 104, and thesecond interconnects 112 as well as fills the cavity 108. The firstinterconnects 104 may be exposed with a number of processes, such as afilm assist molding or a chemical mechanical planarization (CMP). Thefirst side 114 is substantially covered by the first mold compound 124.

Referring now to FIG. 10, therein is shown the structure of FIG. 9 in atape removal phase. The protective tape 702 is removed exposing thefirst non-active side 118 of the first integrated circuit die 102 andthe second side 122 of the substrate 110 for further processing. Thefirst mold compound 124 holds the first integrated circuit die 102 inthe cavity 108.

Referring now to FIG. 11, therein is shown the structure of FIG. 10 asecond die-attach phase. The second integrated circuit die 116 isattached on a die-attach material 1102, such as an adhesive, on thefirst non-active side 118 of the first integrated circuit die 102. Thethird interconnects 120 are attached between the second integratedcircuit die 116 and the second side 122 of the substrate 110.

Referring now to FIG. 12, therein is shown the structure of FIG. 11 in asecond encapsulation phase. The second mold compound 126 forms a centergate mold and encapsulates the second integrated circuit die 116 and thethird interconnects 120. The second mold compound 126 forms a hermeticseal with the first mold compound 124 for the first integrated circuitdie 102 and the second integrated circuit die 116. The second moldcompound 126 covers the second side 122 near the proximity of the cavity108 and does not obstruct the external interconnects 128 of FIG. 1attached to the second side 122.

Referring now to FIG. 13, therein is shown the structure of FIG. 12 inan external connectivity attach phase. The external interconnects 128may be attached to the second side of the substrate 110. The height ofthe second mold compound 126 does not impede connections of the externalinterconnects 128 to the next system level, such as a printed circuitboard. After attachment of the external interconnects 128, singulationprovides the first stackable integrated circuit package system 100.

Referring now to FIG. 14, therein is shown the structure of FIG. 13 in apackage mounting phase. The top package 502 is mounted on the firststackable integrated circuit package system 100 forming the firstintegrated circuit package-on-package system 500. The firstinterconnects 104 and the top external interconnects 516 may be a numberof configurations, such as a peripheral configuration, an arrayconfiguration, a configuration with depopulated locations, or acombination thereof. More than one package or packages of differenttypes may be mounted on a stackable integrated circuit package system,such as the first stackable integrated circuit package system 100.

Referring now to FIG. 15, therein is shown a flow chart of a stackableintegrated circuit package system 1500 for manufacture of the stackableintegrated circuit package system 100 in an embodiment of the presentinvention. The system 1500 includes placing a first integrated circuitdie having an interconnect provided thereon in a substrate having acavity in a block 1502; encapsulating the first integrated circuit die,having the interconnect exposed, in the cavity and along a first side ofthe substrate in a block 1504; mounting a second integrated circuit dieto the first integrated circuit die in a block 1506; and encapsulatingthe second integrated circuit die along a second side of the substratein a block 1508.

It has been discovered that the present invention thus has numerousaspects.

It has been discovered that the stackable integrated circuit packagesystem provides low cost and flexible manufacturing for increasingintegrated circuit content in a minimum space. The use of existingequipments for manufacturing the stackable integrated circuit packageoffers a low cost manufacturing. The external connectivity optionsprovide various integration and stacking options with known good die(KGD) increasing the overall manufacturing yield to decrease the overallmanufacturing cost.

An aspect is that the present invention integrates the bumped devices orstacked bumped devices provides a higher I/O to the next system level,such as a printed circuit board, or more package-on-packageconfigurations while not increasing the overall package size.

Another aspect of the present invention is that the bumps on the bumpeddevices are molded and may be in a number of configurations, such as aperipheral configuration, an arrayed configuration, a configuration withsome depopulated locations, a configuration with different pitches, or acombination thereof. This configuration flexibility allows for differenttypes and multiple stacking options. The configuration may be tailoredto match the requirements of the overall package on the mother board.

Yet another aspect of the present invention is that the bumpedintegrated circuit die may direct signals from the top device tocircuitry of the bumped integrated circuit die and subsequently to theprinted circuit board (PCB) using flex-on-chip (FOC) technology. Thebumped integrated circuit die also provides signal routing from a topdevice stacked on the stackable integrated circuit package to the PCB(daisy chain) using redistribution layer (RDL) technology serving as adummy substrate/interposer. The bumped integrated circuit die furtherprovides signal routing from the top device stacked on the stackableintegrated circuit package, via bumped integrated circuit die circuitry,to the PCB using RDL technology.

Yet another aspect of the present invention is that the flexibility ofintegration and stacking options. The stackable integrated circuitpackage may for numerous stacked integrated circuit package with KGD inthe form of bare dies or packaged devices. Also, the stackableintegrated circuit package may form numerous package-on-packagesolutions with KGD in the form of bare dies or packaged devices.Further, the stackable integrated circuit package may form packagesolutions with a combination of the above mentioned package types, againwith all KGD.

Yet another important aspect of the present invention is that itvaluably supports and services the historical trend of reducing costsand increasing performance. These and other valuable aspects of thepresent invention consequently further the state of the technology to atleast the next level.

Thus, it has been discovered that the stackable integrated circuitpackage system method of the present invention furnishes important andheretofore unknown and unavailable solutions, capabilities, andfunctional aspects for increasing chip density in systems. The resultingprocesses and configurations are straightforward, cost-effective,uncomplicated, highly versatile and effective, can be implemented byadapting known technologies, and are thus readily suited for efficientlyand economically manufacturing stacked integrated circuit packageddevices.

While the invention has been described in conjunction with a specificbest mode, it is to be understood that many alternatives, modifications,and variations will be apparent to those skilled in the art in light ofthe aforegoing description. Accordingly, it is intended to embrace allsuch alternatives, modifications, and variations that fall within thescope of the included claims. All matters set forth herein or shown inthe accompanying drawings are to be interpreted in an illustrative andnon-limiting sense.

1. A stackable integrated circuit package system comprising: a substratehaving a first side and a second side opposite the first side, thesubstrate having a cavity provided therein; a first integrated circuitdie in the cavity with a first interconnect extending out from thecavity without connection and a second interconnect connected to thefirst side; a first mold compound to cover the first integrated circuitdie, the second interconnect, and a portion of the first interconnect; asecond integrated circuit die mounted to the first integrated circuitdie with a third interconnect connected to the second side; a secondmold compound to cover the second integrated circuit die and the thirdinterconnect; and external interconnects, not encapsulated by the secondencapsulant, mounted on the second side.
 2. The system as claimed inclaim 1 wherein the first mold compound to cover the first side.
 3. Thesystem as claimed in claim 1 wherein the first mold compound is a centergate mold on the first side.
 4. The system as claimed in claim 1 furthercomprising a third mold compound to surround the first mold compoundwith the interconnect exposed.
 5. The system as claimed in claim 1wherein the second integrated circuit die has the interconnect providedthereon and the second mold compound exposed the interconnect.
 6. Thesystem as claimed in claim 1 wherein: the first integrated circuit diehaving the interconnect provided thereon in the substrate having thecavity is within the cavity; the first mold compound to cover the firstintegrated circuit die, having the interconnect exposed, in the cavityfills the cavity; the second integrated circuit die is mounted to anon-active side of the first integrated circuit die; the second moldcompound to cover the second integrated circuit die to the substrate isattached to the first mold compound; and further comprising: a firstbond wire between the first integrated circuit die and a first side ofthe substrate; and a second bond wire between the second integratedcircuit die and a second side the substrate.
 7. The system as claimed inclaim 6 further comprising: a top package having a top externalinterconnect; and the top package on the stackable integrated circuitpackage system with the top external interconnect attached to theinterconnect.
 8. The system as claimed in claim 6 further comprising: atop package having a top external interconnect; and the top package onthe stackable integrated circuit package system with the top externalinterconnect attached to the interconnect and the first side.
 9. Thesystem as claimed in claim 6 wherein the second mold compound is acenter gate mold on the second side.
 10. The system as claimed in claim6 further comprising a hermetic seal formed with the first moldingcompound and the second molding compound.